Wi-Fi thermostat with a wireless touch screen controller


The COMPUTHERM B400RF is a wireless Wi-Fi thermostat with touch screen. It can be used to control the device (e.g. boiler) connected to it either remotely through the internet, or locally through its touch screen. This product is an ideal choice to everyone as with its favourable price and its state-of-the-art technology it reduces energy costs while maintaining comfort. It can be easily connected to any gas boiler having a two-wire thermostat connection point and to any air conditioning apparatus or electrical apparatus, regardless of whether they have a 24 V or 230 V control circuit.

The device consists of two units. One is the thermostat (transmitter unit), the other is the receiver unit that controls the boiler. There is a wireless (radio frequency) connection between the two units, so there is no need to build a wire between the thermostat and the boiler and the location of the thermostat can also be changed during use

With the help of this product you will be able to control the heating of your flat, house or holiday home anytime, from anywhere.
It is especially useful if:

  • you are not using your flat or house based on a regular schedule,
  • you are travelling away from you home for an indefinite time during the heating season  
  • you would like to use you holiday home during the heating season.

The simultaneous use of several COMPUTHERM room thermostats and one COMPUTHERM Q4Z zone controller provides the possibility for the thermostats to also control a pump or a zone valve in addition to starting the heater or cooler. This way it is easy to divide a heating / cooling system into zones, thanks to which the heating / cooling of each room can be controlled separately, thus greatly increasing comfort. Furthermore, the zoning of the heating / cooling system will greatly contribute to the reduction of energy costs, as due to this only those rooms will be heated / cooled at any time where it is required.

Important functions:

  • Wireless thermostat with touch screen
  • User interface: touch screen, mobile application, website
  • The thermostat is freely portable within range
  • Can be controlled remotely
  • Easy switching between cooling and heating modes
  • Humidity measurement
  • Selectable switching sensitivity
  • Timer function
  • Setting alarm limits
  • Multi-user control

Technical data:

  • User interface: touch screen, mobile application, website
  • Adjustable temperature range: -55 °C to +100 °C (in 0.1 °C increments)
  • Temperature measurement accuracy: ±0.5 °C (at 25 °C)
  • Selectable switching sensitivity: 0 °C to ±74 °C (in 0.1 °C increments)
  • Thermometer calibration range: ±9.9 °C (in 0.1 °C steps)
  • Humidity measurement accuracy: ±2% RH (at 25 °C, from 20% to 80% RH)
  • Supply voltage of the thermostat: micro USB 5 V DC, 1 A
  • Supply voltage of the receiver unit: 230 V AC; 50 Hz
  • Switchable voltage: max. 30 V DC / 250 V AC
  • Switchable current: 16 A (4 A inductive load)
  • Operating frequency: RF 433 MHz, Wi-Fi (b/g/n) 2.4 GHz
  • Transmission distance of the RF communication: approx. 250 m in open terrain
Computherm - Wi-fi termosztátok -  COMPUTHERM B400RF - Quantrax Kft.
Computherm - Wi-fi termosztátok -  COMPUTHERM B400RF - Quantrax Kft.
Computherm - Wi-fi termosztátok -  COMPUTHERM B400RF - Quantrax Kft.
Computherm - Wi-fi termosztátok -  COMPUTHERM B400RF - Quantrax Kft.

Download the most important documents related to the product

To control this product Download the the COMPUTHERM B Series app for free from here:


Take a look at our videos displaying the use of the product: 


What purpose can the COMPUTHERM B400RF Wi-Fi thermostat be used for?

The COMPUTHERM B400RF Wi-Fi room thermostat has been specifically designed to control heating and cooling systems. The thermostat connects your smart phone, laptop or computer to the device to be controlled remotely.  With the help of B400RF you can set the temperature of your home hour by hour, and you can set and control it via the Internet. The wireless temperature sensor sends the measured temperature to the connected B400RF.

Turning  on  and  off  the  controlled  appliance  allows  you  to  maintain  constant  comfortable temperature without suffering any unnecessary energy losses. This product is especially useful when you do not use your flat or house according to a predefined schedule, you leave your home for an uncertain period of time during the heating season or you intend to use your holiday home during the heating season as well.

In addition, the thermostat is also suitable for controlling electrical and electronic devices which can be turned on and off by interrupting and resuming power supply.

How B400RF will reduce the total amount of your bill?

With B400RF you can set your desired temperature for every hour of the day and night. This way the temperature in your home always meets your requirement. It provides comfort without consuming energy unnecessarily. It always consumes as much energy as needed and you can save up to 30 percent of your heating costs. In addition, remote control can also save energy for you because this way you can remotely turn off the device to be controlled when you are away then turn it on later.

What type of appliances can be controlled by COMPUTHERM B400RF?

COMPUTHERM B400RF type switching-mode room thermostat is able to control vast majority of the boilers and air-conditioning equipment available on the Hungarian market. It can be easily connected to any gas boiler or air-conditioning equipment which has a two-wire room thermostat connection point, irrespective of whether it has a 24 V or 230 V control circuit. In addition, the thermostat is also suitable  for  controlling  electrical  and  electronic  devices  which  can  be  turned  on  and  off  by interrupting and resuming power supply.

Can B400RF be used for air-conditioning equipment?

Owing to its characteristics, B400RF is most suitable for controlling heating systems but it can also be used to control air-conditioning equipment. For controlling a cooling system the working mode of the thermostat should be changed in its settings.

Can B400RF be used to control a heating system only?

No, the appliance is able to control air-conditioning equipment and any other device which can be operated only by its ON/OFF function. In the settings menu it is possible to switch between the different working modes.

What type of battery / mains supply is required for the operation of B400RF?

To operate the central unit with a color touch display, a voltage of 5 V DC is required, which can be provided by connecting the mains adapter and micro USB cable included in the basic package of the device to a 230 V mains power source. The receiver works directly from a 230 V mains power source. No batteries are required to operate the device.

Where can you buy it?

Search this product at our reseller partners. The list of our reseller partner is available at the following link:

Where you can find the Instruction Manual of the appliance?

Instructions for installing and operating B400RF are available at the following page:

From where can you download mobile application of B400RF?

If you use an Android operating system you can download the application from Google Play Store. If you use iOS operating system you can download the application from App Store. The name of the application is COMPUTHERM B Series.

How many B400RF appliances can be controlled from a mobile profile?

The number of the appliances is unlimited. Every commissioned B400 appliance can be added to your phone application and can be controlled from your phone.

Will several B400RF thermostats used in the same flat disturb each other’s operation?

No. Each thermostat is connected to the local Wi-Fi network separately and this solution guarantees reliable and trouble-free operation of the appliances. Each thermostat and accompanying temperature sensor(s) has its own security code which ensures reliable and trouble-free operation of the appliances. Each receiving unit receives signals only from the temperature sensor that has the same security code. As a result, practically unlimited number of appliances can be used in the immediate vicinity of each other without causing any problem in the communication between the devices.

What is the expected lifetime of the batteries when they are used for B400RF?

It depends on the type of the batteries and the distance between the temperature sensor and the central unit but the average lifetime is 18 to 24 months.

Is it absolutely necessary to have a Wi-Fi connection with Internet access for using B400RF?

To install and modify the settings it is necessary to have a Wi-Fi network with Internet. After that the thermostat can work without Wi-Fi connection according to its settings. While the thermostat is inaccessible via the Internet, you can manually turn on and off it with a button located on the side of the appliance as described in Subchapter 7. e) of the Instruction Manual. Even so to use the thermostat comfortable it is recommended to connect the thermostat to a stable Wi-Fi network with Internet.

How can you connect the appliance?

For more detailed information please refer to the Instruction Manual of the appliance or watch the video which demonstrates installation and use of the appliance:

Where to locate the temperature sensor and the main unit?

It is expedient to locate the temperature sensor where you stay regularly or a long period of time so that the sensor is oriented in the direction of the natural ventilation of the room but is not exposed to draught or extreme heat (e.g. sunlight, refrigerator, chimney, etc.). Its optimal location is at a height of 1.5 m from the floor level.

When choosing the location of the main unit you should remember that bulky metal objects (e.g. a boiler, buffer tank, etc.) and metal building structures may have an adverse effect on propagation of radio waves. If it is possible, in order to ensure trouble-free RF connection, we recommend that you install the main unit at a height of 1.5 to 2 m and at a distance of 1 to 2 m from the boiler or other bulky metal constructions. We recommend that you check reliability of Wi-Fi connection at the place selected before installing the main unit. Do not install the main unit under the housing of the boiler or near hot pipes because it may damage the parts of the device or compromise Wi-Fi connection. We also recommend that the power is preferably supplied to the main unit from a socket other than that of the boiler (and from another phase, if it is possible), and line power must not be supplied to the main unit from the boiler on any account.  To avoid electric shock, entrust a specialist with connecting the receiver unit to the boiler!

Can more than one temperature sensor be connected to a single appliance?

Yes, you can connect several more wired and wireless temperature sensors simultaneously to a single appliance according to the Instruction Manual, but you can control the heating process only by one of the sensors, while the other sensors can only be used to provide information.

What should do if the thermostat switches but the 230 V does not appear on the output?

The device has potential-free output connection points, so in normal case the 230 V does not appear on its output, only the 2 attached wires are connected or disconnected from each other when the thermostat switches. If you wish to have the 230 V on the output when the thermostat switches then you should connect the phase wire to the NO of COM connection point so the thermostat according to the manual instruction. Before you connect the phase wire, make sure that it is disconnected from the electric power supply. The device must be installed and connected by a qualified professional.

What should you do if the signal of your Wi-Fi router is weak and thus B400RF is outside the range of the router?

If it is possible, put the router closer to your B400RF appliance. Another option is to place a Wi-Fi signal booster between the router and B400RF to extend the range of the router.

What should you do if you encounter a problem related to the Wi-Fi network?

If the appliance cannot be controlled via the Internet because the application indicates that the appliance is inaccessible and does not respond to the modifications then the connection between the appliance and the web interface has been interrupted. This situation may be due to several reasons. The problem is most probably caused by the Wi-Fi router being used. It is expedient to restart the routers from time to time by interrupting and restoring power supply. In most of the cases this type of problems is solved by restarting the router. If the appliance is still inaccessible at the front end after a few minutes have elapsed then it is recommended that the appliance is reconnected to the Wi-Fi network according to Chapter 4.5 of the Instruction Manual. If the connection is successful but the appliance is still inaccessible then it is recommended that the router is set to factory default, because it may occur that the device cannot be connected to the Internet because of some settings. While the thermostat is inaccessible via the Internet you can manually turn it On/Off according to the Subchapter 7. e) of the manual.

How does this product continue to function after a power outage?

After the power supply is restored the appliance continues to function according to the settings defined before the power outage (or according to a preset program in programmable mode).

How can default setting of the appliance be restored (reset)?

Press and hold the button located on the side of the product for 3 seconds.  Following this, release the button for 1 second then press again and hold it down for 3 seconds.  Now you can release the button and the product is set back to factory default setting.